Treated wastewater (TWW) irrigation is increasingly used in arid regions, and its effects on soil salinity are well documented. However, its influence on soil carbon fractions, aggregation, and stable carbon (δ13C) and nitrogen (δ15N) isotopes remains poorly understood. This study evaluated the impacts of TWW irrigation on soil total carbon (TC), soil organic carbon (SOC), active carbon (AC), inorganic carbon (IOC), water-stable aggregates (WSA), δ13C, δ15N, and aggregate-associated carbon and nitrogen isotopes across multiple soil depths. Compared to freshwater (FW), TWW significantly increased AC at 0-15, 15-30, and 30-45 cm by 16.8%, 23.0%, and 32.4%, respectively, and enhanced SOC by 31.7% at 45-60 cm depth. The >2 mm WSA increased by 16.7% and 48.9% at 0-15 and 30-45 cm, respectively, under TWW irrigation. TWW also enhanced aggregate-associated carbon at depths of 0-15 and 15-30 cm and enriched δ15N at depths of 30-45 and 45-60 cm. In contrast, aggregate-associated δ13C decreased at 30-60 cm, and δ13C values across aggregate fractions were consistently lower than bulk soil at depths of 15-60 cm. Variations in SOC and AC were over 30% greater in subsoil than topsoil, whereas δ13C and δ15N showed no comparable depth trend, indicating a decoupling between soil carbon accumulation and organic matter quality. Structural equation modeling further revealed that soil total carbon, δ13C, and δ15N jointly act as dominant drivers of WSA, highlighting that aggregate stabilization under TWW irrigation is governed by integrated carbon quantity and transformation processes. Overall, TWW irrigation enhances subsoil carbon accumulation and aggregate stability while influencing soil isotopic composition, revealing new insights into soil carbon dynamics in arid agroecosystems.

Dryland agriculture contributes substantially to greenhouse gas (GHG) emissions, primarily due to flood irrigation, excessive nitrogen fertilization, and intensive soil disturbance. However, the influence of climate-smart agriculture (CSA) practices in mitigating GHG emissions under dry conditions remains inconsistent. This meta-analysis was conducted by reviewing 87 peer-reviewed papers to assess the impact of CSA practices, such as no-tillage (NT), drip irrigation (DI), plastic mulching (PSM), straw mulching (STM), and nitrogen fertilization (NFY), on soil organic carbon (SOC) content, global warming potential (GWP), GHG intensity (GHGI), and crop yields in arid and semi-arid agroecosystems. DI was the most effective single practice, reducing CO2, N2O, GWP, and GHGI by 9.8 %, 54.7 %, 9.5 %, and 10.6 %, respectively. Compared to conventional tillage (CT), NT with straw retention (NTS) significantly increased SOC content by 14.8 % and wheat yield by 5.2 %, while long-term (>5 years) NT reduced GWP and GHGI by 14.2 % and 14.1 %, respectively. Conversely, STM and high NFY rate increased GWP by 27.7 % and 41.5 %, respectively. Although the high NFY rate increased overall crop yield by 70.6 %, indicating at a substantial environmental cost. In contrast, a low NFY rate reduced GHGI by 42.6 %, suggesting a viable mitigation pathway. Overall, these findings underscore a fundamental trade-off between yield and emissions, indicating that integrating precise nutrient management, drip irrigation, and no-tillage with optimized residue retention can provide a synergistic strategy to enhance productivity while simultaneously mitigating GHG emissions in dryland agroecosystems.

Although soil health indicator is extensively examined worldwide, Japan has yet to establish a soil health assessment framework calibrated to the unique properties of Andosols. In this study, we evaluated a long-term (19-year) organically managed soybean field and generated soil health scores using a cumulative normal distribution function to develop a site-specific benchmark. Treatments were tillage (no-tillage, moldboard plowing, and rotary tillage), cover crop (rye, hairy vetch, and fallow), and the addition of fertilizer or biochar in four replications. Intensive tillage reduced soil health, with soil health score under moldboard plowing significantly lower than no-tillage during 2020–2022 (p < 0.05). No-tillage with cover crop and biochar enhanced soil health status by sustaining soil organic carbon (SOC) at 3.8–4.8%. Overall soil health score was positively correlated with SOC (r = 0.7; p < 0.01), while higher soil health score was strongly associated with reductions in net global warming potential (rs = − 0.95; p < 0.01). SOC emerged as one of the most influential indicators, directly influenced soil ß-glucosidase activity (r = 0.84, p < 0.001), substrate-induced respiration (r = 0.7, p < 0.001), NO3– (r = 0.65, p < 0.05), and EC (r = 0.36, p < 0.01). Although NT-based systems may not achieve the highest yields due to interannual variability, they may offer substantial environmental benefits by contributing to long-term climate change mitigation.

With the dissemination of conservation agriculture,no-tillage(NT)and cover crops have been widely adopted globally.However,their effects on greenhouse gas(GHG)emissions are controversial.Biochar is posited to mitigate climate change by increasing carbon(C)sequestration and decreasing GHG emissions in soil.To investigate the comprehensive effect of NT,cover crop,and biochar on soil organic C(SOC)sequestration and net global warming potential(GWP),a split-split-plot experiment was conducted in the experimental field at the Center for International Field Agriculture Research and Education,Ibaraki University,Japan.The experiment involved various combinations of two tillage methods,NT and moldboard plowing(MP),two cover crop treatments,fallow(FA)and rye(RY),and two biochar treatments,biochar application(WB)and no biochar application(NB).The NT and RY treatments demonstrated a trend of increasing N2O emission,while WB tended to reduce the N2O emission in NT plots.Compared with the MP-FA-NB treatment,the NT-RY-WB treatment increased SOC stock(0-30 cm)by 23.2％in 2020 and 30.2％in 2021,indicating that this combination promoted C sequestration.Due to the heightened SOC stock,the net carbon dioxide(CO2)retention effectively compensated for the GWP arising from non-CO2 emissions.Consequently,the combination of NT,RY,and WB positively contributed to a decreased net GWP in the soybean field(-1 231 and-2 767 kg CO2 equivalent ha-1 year-1 in 2020 and 2021,respectively).These findings highlight the considerable potential of the combination of NT,RY,and WB for SOC sequestration and net GWP decrease,positioning it as an environmentally beneficial agricultural system for mitigating climate change during long-term food production in Asia.

ABSTRACT No‐tillage (NT) is promoted as a climate‐change mitigation practice for its potential to enhance soil organic carbon (SOC) sequestration. Yet the effects of long‐term NT legacies and residue application methods on new C stabilization, priming effects (PE), and net C balance in humid Andosols remain unclear. Here, we conducted a 1‐year field incubation experiment using 13C‐labelled plant residue (C/N = 25.8) in an Andosol collected from long‐term NT and conventional tillage (CT) sites in Japan. Residues were applied under three treatments (n = 4): surface application on intact NT soil (NTSA), surface application on CT soil with disrupted structure due to both tillage and sampling effects (CTSA), and incorporation into CT soil with similarly disrupted structure (CTMIX), and controls without residue additions (NTCK and CTCK). Soil‐ and residue‐derived CO2 emissions were measured over 375 days. Soils were collected at days 28, 91, 183, and 375 to quantify residue‐derived C remaining and microbial biomass C. PE and net C balance were also assessed. Surface residue application (NTSA and CTSA) resulted in greater residue mineralization than CTMIX, indicating that surface‐application‐driven CO2 emissions were stimulated regardless of tillage history. PEs were greater in CTSA (+2690 mg C kg−1 soil) than in NTSA or CTMIX (+154 and −518 mg C kg−1 soil, respectively). In the surface layer (0–2.5 cm), the ratio of microbially immobilized residue‐derived C to the total MBC was higher in CTSA than in NTSA, indicating that long‐term NT may reduce microbial responses and consequently suppress PE. Accordingly, NTSA and CTMIX showed a more favourable net C balance than CTSA. These results indicate that long‐term NT promotes SOC retention through soil structural preservation and microbial adaptation to surface C inputs, whereas residue mixing may compensate tillage‐induced SOC losses. Overall, long‐term NT legacies and residue application methods regulated SOC dynamics through distinct mechanisms in humid Andosols.

Long-term no-tillage (NT) alters soil habitat and biota organization, yet its consequences for cross-kingdom interactions and soil organic carbon (SOC) storage in humid Andisols remain unclear. We investigated a 22-year field experiment comparing NT and conventional tillage (CT), with and without cover cropping, across topsoil (0–5 cm) and subsurface soil (5–15 cm) over three seasons. Soil physicochemical properties, microbial biomass C (MBC), β-glucosidase activity (BG), bacterial and fungal gene copy numbers were analyzed. We characterized bacterial, fungal, protistan, and nematode communities, inferred SPIEC-EASI-based cross-kingdom networks, and quantified microbial necromass as an indicator of accumulated microbial-derived SOC.NT exerted stronger effects than cover cropping and created a topsoil-oriented system. In topsoil, NT increased SOC, moisture, available N & P, MBC, BG, and bacterial and fungal gene copies, whereas CT maintained relatively higher values in subsurface soil. Bacterial, but not fungal, copies strongly correlated with MBC (r = 0.86***), indicating a bacteria-associated agroecosystem. Tillage significantly altered all four biotic groups, and NT topsoil bacteria were enriched in taxa associated with polymer decomposition. NT topsoil also developed a larger, denser, and more robust network than CT topsoil, with more bacterial nodes, within-bacteria links, and bacteria–protist/nematode links. Functional composition of protistan and nematode nodes indicated a more developed bacteria-based predator–prey web under NT. Procrustes analysis suggested shared edaphic filtering for bacteria and fungi, whereas bacteria–protist/nematode concordance reflected bacteria-based trophic coupling that was maintained under NT but weakened under CT. Despite these shifts, BG/MBC remained similar, indicating limited changes in microbial metabolic efficiency. In contrast, bacterial and fungal necromass increased under NT in topsoil but decreased in subsurface soil. These results indicate that, in humid Andisols, NT promotes topsoil carbon storage mainly by increasing microbial biomass, strengthening bacteria-centered trophic coupling, and enhancing microbial necromass accumulation, rather than by shifting microbial metabolic efficiency.

Increasing freshwater scarcity and salinity risks in arid regions worldwide necessitate alternative water sources and salt-tolerant crops for sustainable agriculture. However, the effects of such water sources on crop performance and root-zone soil salinity need to be evaluated before advocating the wider use of saline water. This two-year field study used a split plot design to evaluate the effects of saline municipal treated wastewater (TWW) and freshwater (FW, control) (main-plot factor) on the performance of three spring canola (Brassica napus L.) cultivars (CP930RR, CP955RR, and CP9978TF, subplot factor), and root-zone soil salinity (top 0.6 m). Results indicated that canola seed and straw yields did not differ significantly between TWW and FW across three cultivars. Across treatments, seed yield ranged from 2327 kg ha−1 under FW to 2675 kg ha−1 under TWW for CP9978TF, while the straw yield ranged from 5095 kg ha−1 for CP955RR under TWW to 6471 kg ha−1 for CP930RR under TWW. After two growing seasons, average soil salinity (ECe) increased from a baseline level of 2.3 dS m−1 to 3.5 dS m−1 under FW and 4.6 dS m−1 under TWW, while SAR rose from 4.2 to 5.2 and 7.5, respectively. Despite these increases, ECe and SAR remained well below canola thresholds for salinity (9.7 dS m−1) and sodicity (SAR 13). Salinity and sodicity increased with time and depth, particularly under TWW, indicating progressive salt accumulation and redistribution within the soil profile. The findings demonstrated that saline alternative water sources, particularly treated wastewater (TWW), can supplement or partially replace conventional freshwater irrigation and thereby contribute to the sustainability and resilience of irrigated agriculture in water-scarce regions.

Abstract Long‐term sustainability of organic crop cultivation depends on management systems that simultaneously maintain soil fertility and productivity. However, the plausible combined effects of tillage systems, cover crops, and biochar under varying organic rotation systems remain ambiguous, especially in soils containing volcanic ash with inherently high organic matter. Thus, a two‐cropping‐year field experiment (2022–2024) was conducted at a site with >20 years of no tillage (NT) research history in Kanto, Japan. It evaluated the interactive effects of tillage methods (moldboard plow [MP], rotary tillage [RT], and NT), winter cropping systems (wheat [ Triticum aestivum L.] monoculture at 50 or 100 kg ha −1 , or wheat–hairy vetch [ Vicia villosa Roth] mixture at 50 kg ha −1 each), and biochar application (0 or 8 t ha −1 ) within an organic soybean [ Glycine max (L.) Merr.]–wheat rotation system. The soybean yield under NT was comparable to or significantly higher than under RT, but wheat yield was greater under MP. No‐tillage significantly increased the soil organic carbon (SOC) levels of the 0–7.5 cm layer, lowered bulk density, and improved surface soil structure. Biochar further enhanced the SOC across all soil depths, but not short‐term yields. Cover crops increased SOC and wheat plant height, suggesting improved nutrient cycling, although the effects on yield were limited. These findings demonstrate that integrating NT and biochar supplementation can enhance SOC sequestration without compromising legume yield under organic conditions; however, cereals may require periodic tillage to maintain productivity. This study provides quantitative evidence for designing crop‐specific conservation systems and carbon (C) farming strategies for use with Andisols.

Context: Organic farming is widely regarded as a key strategy for achieving sustainable development in agriculture, with its sustainability closely linked to the management practices employed. Assessing the sustainability of organic cropping systems under varying management practices is essential to identify and promote the most sustainable options. Objective: This study investigated the effects of tillage and cover crop management on the efficiency and sustainability of a regenerative organic cropping system. It aimed to determine the most suitable combination of tillage and cover crop management for achieving high sustainability. Methods: Three tillage methods-moldboard plowing (MP), no-tillage (NT), and rotary tillage (RT)-and two cover crop strategies-fallow (FA) and rye (RY)-were evaluated in an organic soybean system. Sustainability was assessed using emergy evaluation based on life cycle assessment (LCA) methodology. Soil organic matter and inorganic nutrients were included in the emergy accounting. Results and conclusions: The NT system significantly reduced nonrenewable inputs by 44.0 % and 8.2 % compared to MP and RT, respectively, though it resulted in a yield reduction of 26.9 % and 26.7 %. However, RY management mitigated this reduction, with NT-RY achieving 38.6 % higher yields compared to NT-FA. NT-RY also increased soil organic matter and potassium by 53.5 %, leading to higher total system output. NT-RY demonstrated the highest production efficiency, with the lowest unit emergy value (UEV = 3.32E + 05 sej J-1). The emergy sustainability index of NT was 4.5 % and 1.3 % higher than MP and RT, respectively, while RY further enhanced ESI across the system. Significance: LCA-based emergy evaluation is a powerful tool for comparing the sustainability of agricultural management practices. These findings identify NT-RY as a promising approach for advancing sustainable development in organic farming, offering valuable insights for organic growers striving to enhance agricultural sustainability.

Regenerative agriculture prioritizes soil health to enhance ecosystems and crop production. No-tillage organic farming with cover crop rotation improves sustainability. However, economic barriers must be considered. This study evaluated the involvement of biochar into long-term no-tillage combined with cover crop as a regenerative organic approach on soil health and carbon sequestration as well as to assess the economic viability of this farming system. The field experiment was designed as a randomized complete block with a split-split plot arrangement consisting of different tillage practices (no-tillage, rotary cultivator, and moldboard plowing), cover crop (rye, hairy vetch, and fallow), and biochar applications (with and without biochar), in four replications. The study also included two farming scenarios, soybean and soybean + rice production, for economic analysis. Results showed that incorporating biochar into the continuous no-tillage with cover crop rotation increased soil organic carbon and its stock in the topsoil profile (0-30 cm), improved soil health indicators by reducing soil bulk density and penetration resistance, and increased microbial activity, thereby promoting nutrient cycling. Soybean yield varied under the no-tillage system, resulting in a low benefit-cost ratio; however, the integration of soybean with rice production improved this ratio in organic farming-based no-tillage management. Compared with moldboard plowing, no-tillage with rye resulted in the lowest cost of soil organic carbon production. Given these findings, integrating biochar into long-term no-tillage management centered on regenerative organic farming would improve environmental quality and provide economic advantages, strengthening the resilience of natural system, specifically in Andosol, Japan.

In organic farming, intensive tillage for weed control can degrade soil structure and reduce organic carbon and water retention. Organic no-tillage with surface mulch offers a potential solution, but its long-term effectiveness in Andosol soil remains poorly understood. This study evaluated the long-term effects of organic no-tillage practices combined with organic mulch on soil organic carbon (SOC) content and storage, water-stable aggregate distribution (WSAD%), aggregate-associated carbon, carbon stabilisation within aggregates, bulk density (BD), mean weight diameter (MWD), and soil water retention. The field experiment was conducted using a randomised complete block design with four replications, comparing two treatments: no-tillage (NT) and conventional tillage (CT), both supplemented with organic mulch. Compared with CT, NT treatment yielded a 65.4% increase in SOC content and a 16.9% decrease in bulk density in the 0-5 cm surface layer, triggering a 16.3% improvement in SOC accumulation in the 0-20 cm soil depth. Furthermore, WSAD and MWD increased at the 0-5 cm, 5-10 cm, and 10-15 cm soil depths. Compared with CT, at all depths, aggregates exceeding 4 mm showed high SOC content and increased SOC stock within macroaggregates in NT, with field capacity and total plant available water (PAW) content also increasing. This study emphasises the critical role of SOC in enhancing PAW directly and the mean weight diameter in indirectly improving it by regulating field capacity. Overall, in organic farming, NT with residue retention markedly facilitates the overall improvement of SOC, soil structure stability, SOC stabilisation within macroaggregates, and soil water retention.

With the dissemination of conservation agriculture, no-tillage (NT) and cover crops have widely been adopted globally. However, their effects on greenhouse gas (GHG) emissions are controversial. Biochar is posited to mitigate climate change by increasing carbon (C) sequestration and decreasing GHG emission in soil. To investigate the comprehensive effect of NT, cover crops, and biochar on soil organic carbon (SOC) sequestration and net global warming potential (GWP), a split-split-plot experiment was conducted. The experiment involved various combinations of two tillage methods (NT; Moldboard plowing, MP), two cover crop treatments (Fallow, FA; Rye, RY), and two biochar treatments (with biochar application, WB; no biochar application, NB). NT and RY demonstrated a trend of increasing N2O emission, while WB tended to reduce the N2O emission in NT plots. NT–RY–WB increased the SOC stock (0–30 cm) by 23.2% in 2020 and 30.2% in 2021 compared with MP–FA–NB, indicating that this combination promoted C sequestration. Due to the heightened SOC stock, the net carbon dioxide (CO2) retention effectively compensated the GWP arising from non-CO2 emissions. Consequently, the triple combination of NT, RY and WB positively contributed to a decreased net GWP in the soybean field (−1231 kg CO2 equivalent ha−1 year−1 in 2020 and −2767 kg CO2 equivalent ha−1 year−1 in 2021). These findings highlight the considerable potential of the combined NT–RY–WB for SOC sequestration and net GWP decrease, positioning it as an environmentally beneficial agricultural system for mitigating climate change in Asia’s long-term food production.

The increase in soil carbon sequestration under long-term no-till (NT) and cover crop management has been shown to form part of a sustainable agricultural management practice system. Along with the increase in soil organic carbon (SOC), soil respiration in this system was also enhanced by the increased soil temperature through the decomposition that causes carbon loss from the soil. To overcome this issue, biochar can be applied. However, the addition of biochar into this system is not well studied. Therefore, the aim of this study was to investigate the effect of this system on soil respiration. The experiment was conducted at the Center for International Field Agriculture Research & Education, Ibaraki University. Long-term tillage practices, such as NT and moldboard plowing (MP), cover crops such as rye (RY) and fallow (FA), and biochar application such as with biochar (WB) and no biochar (NB) were applied to a split-split plot in a randomized complete block design with four replications. The daily CO2 flux was measured every week at 9:00-11:00 a.m. The daily soil respiration was affected by tillage and cover crop with NT practice had significantly higher daily CO2 flux than that of MP (23.8%-107.4% and 38.0%-107.8%), while RY had higher flux than that of FA (11.9%-81.2% and 34.9%- 65.4%) in 2020 and 2021 soybean growing season, respectively. Additionally, in the 2020 cover crop growing season RY also increased daily CO2 flux approximately 41.8%-88.2% compared to FA. Biochar addition significantly reduced soil respiration in soybean and cover crop seasons compared to NB by 24.0%-50.7% and by 25.9%-48.3%, respectively. This reduction in soil respiration by the biochar decreased annual CO2 emissions by 17.6% and 13.0% in 2020 and 2021. The values of these emissions ranged from 9.6 Mg ha-1 for MP FA WB to 18.9 Mg ha-1 for MP RY NB in 2020 and from 7.5 Mg ha-1 for MP FA WB to 13.7 Mg ha-1 for NT FA NB in 2021. This study highlights the crucial role of biochar in reducing soil respiration and enhancing SOC sequestration. The addition of biochar into this system was able to reduce soil respiration by regulating the soil temperature, soil moisture, and protect the SOC from decomposition. Biochar addition also increased the SOC and decreased the soil bulk density, which improves soil porosity. Therefore, these findings would be very useful to be included within the global scenario of soil organic matter management.

Organic agriculture has the potential to contribute to environmental conservation, although its impact varies depending on management practices. To investigate the effects of no-tillage (NT) combined with a rye (RY) cover crop on energy efficiency and carbon footprint (CF) in soybean production, a four-year experiment was conducted. Three tillage methods [moldboard plowing (MP), NT, and rotary tillage (RT)] and two cover crop treatments [fallow (FA) and RY] were compared. NT had 39.6% and 34.0% lower energy input compared with MP and RT, respectively, due to reduced fossil fuel consumption. However, NT also showed decreased soybean yield compared with MP and RT. Nonetheless, RY cover crop management mitigated yield reduction in the NT system, with the yield of NT-RY being 20.4% higher than that of NT-FA, although not significantly different. NTRY exhibited the highest energy use efficiency, with high energy outputs from yield and low energy inputs. Moreover, NT-RY resulted in a 3.5% increase in soil organic carbon stock, offsetting total carbon dioxide (CO2) equivalent emissions, leading to the lowest CF (-1892.99 kg CO2 eq ha-1) and yield-scaled CF (-1.44 kg CO2 eq kg-1) among all treatments. Therefore, NT-RY management, with its high yield and energy efficiency and low CF, has the potential to be an environmentally friendly and sustainable cropping system for achieving cleaner agricultural practices in organic farming.

No-tillage (NT) combined with a cover crop is a climate-smart agricultural practice that eliminates nearly all physical disturbance of the soil surface and increases soil aggregation and soil organic carbon (SOC); however, the response of SOC and soil water retention (SWR) to long-term NT and cover crops systems in the volcanic ash Andosol soil of Japan has not been well addressed. This study aimed to evaluate the effect of NT and moldboard plow (MP) tillage systems combined with rye (RY) and fallow (FA) cover crop treatments on SOC, active carbon (AC), water-stable aggregates, aggregate stability index, mean weight diameter (MWD), bulk density, aggregate -associated carbon, and SWR. NT significantly increased the > 4 and 2 mm aggregates, aggregate-associated C at the 0-2.5 and 2.5-5 cm depths, field capacity, and SWR between 0 and 15 cm. RY cover crops significantly increased aggregate-associated carbon at the 2.5-5 and 5-10 cm depths in both NT and MP and SWR at the 10-15 cm depth. NT combined with RY significantly increased SOC and AC in the surface layer and volumetric water content at all soil depths. Path analysis revealed that SOC and MWD were correlated with easily plant-available water (EPAW) and field capacity under the NT system and is the primary reason for the observed increase in SWR. Thus, the NT system increased plant residue, reduced soil evaporation, increased SOC content and SWR, and bonded soil microaggregates into macroaggregates better than the MP system. The use of an RY-based NT system is an effective climate-smart agriculture practice that reduces the drought effects brought on by climate change.

No-tillage (NT) (or zero-tillage) has been widely used to mitigate the adverse effects caused by intensive tillage. However, the long-term effectiveness of NT is highly dependent on agriculture field management, soil type, and climatic conditions. NT under different climatic condition fluctuations and soil conditions has not also been considered adequately in Asia. Furthermore, the high demand for food production in Asia requires a deeper understanding of the impact of NT on soil properties and crop production. Therefore, this meta-analysis was conducted using 64 peer-reviewed articles to evaluate the effects of NT on soil organic carbon (SOC), soil carbon storage, mean weight diameter (MWD), bulk density, water-stable aggregates, water content, other soil chemical properties, and yield responses. Our results showed that NT significantly increased SOC content overall than conventional tillage (CT). Likewise, as observed at a 0-10 cm soil depth, SOC content significantly increased by 77.0% in NT compared to CT. Alternatively, although overall, NT favoured the accumulation of soil C by 53.2% than CT, and this difference was even more impressive at the 0-10 cm layer by 77.0% than CT. Moreover, overall NT significantly increased MWD, soil available P, and >2 mm aggregates than CT. In contrast, even though NT did not significantly decrease smaller than the 0.25 mm aggregates than CT in the 0-10 cm layer, NT increased exchangeable K by 81.0% than CT. Results also showed that while NT and CT had no significant effects on crop yield, NT slightly increased soybean and wheat yield, and CT increased rice and maize yield than NT. Based on these results, NT is proposed as a promising practice to enhance soil quality and is plausible to increase crop yield in Asia.

The study was carried out to determine the effect of organic and inorganic fertilizers on tomato yield and soil quality. The study was performed in a randomized complete block design consisting of 7 treatments with 3 replications in the research farm, Shaikh Zayed University, Khost, Afghanistan. The fertilizers treatments were T1, organic fertilizer (5 t/ha); T2, organic fertilizer (10 t/ha); T3, urea (150 Kg/ha); T4, urea (200 Kg/ha); T5, mixed fertilizers (organic fertilizer 3 t/ha + urea (100 Kg/ha); T6, mixed fertilizers (organic fertilizer 6 t/ha + urea (70 Kg/ha) and T7 a control. Results indicate that applications of inorganic fertilizers with a combination of organic fertilizers increased tomato yield and improves the nutrient status of the soil. T5 showed the highest yield of tomato and followed by T4 treatment, which were 33.1 and 31.7 t/ha respectively. The lower yield were obtained in T7 and T1 treatments. The highest plant heights (205.0 and 199.0 cm) were obtained in T5 and T4 respectively, while the lowest plant heights were obtained in T1 treatment and followed by T7 treatment. Similarly, we found that a combination of both inorganic and organic fertilizers application also is the best strategy to improve soil nutrients, maintain soil fertility. Soil P2O5 and K2O, where the highest amounts were obtained in T5 and followed by T6, which were 26.5, 22.5 and 44.5 and 41.5 mg/L respectively. The control treatment had the lowest amount of P2O5 and K2O. Therefore, this study suggests that an appropriate amount of organic fertilizer with inorganic fertilizer not only increased tomato yield but also improve soil fertility.

Pesticides are a hidden threat to humans, animals, insects, as well as to all ecosystems. They control pests and play an important role in crop productivity and prevent vector borne-diseases in humans, but they also extremely pollute our surroundings. These toxic substances are found in soil, water, air, plants, food and feed. Their residues enter plants and animal products and accumulate in humans and animals by the food chain. They endanger our lives and put down our health, as well as demolish beneficial organisms in the environment. This paper expresses a piece of information that has been obtained from reviewing academic papers, books and other sources. People take these toxic chemicals from water, air, and agricultural products, as well as their surroundings. They are stored in humans and animals’ tissues or excreted by different routes, but their adverse effects have no end. Brain, kidneys, skin, gastrointestinal, liver, lungs, spleen and every organ of humans are suppressed by them. They cause various diseases, cancers, mutations, as well as lead to death. These chemicals destroy honeybees’ colonies and decrease pollinator’s populations. Additionally, birds, wildlife and soil organisms are extremely suppressed by the heavy application of pesticides. They damage human beings, animals, pollinators, honeybees, and soil microorganisms. Increasing the application of pesticides decreases the population of pollinators, honeybees, and other beneficial organisms, as well as impacts human health. If these living organisms are diminished, our lives are threatened by food shortage, a collapsed economy, and increased food and feed demand, therefore new crises including famine and diseases put down our prosperity. All pesticides should be used cautiously and need to develop a new type of pesticides that do not harm seriously our environment.

In organic farming, intensive tillage for weed eliminating may cause physical and biological soil degradation. Weed residue mulch can be used to stabilize the organic carbon in the soil by improving soil aggregation and increasing microbial activity. However, the effectiveness of weed mulch in no-tillage (NT) and conventional tillage (CT) systems remains unclear. Therefore, we studied the influence of clipped weed mulch (CM) and no mulch (NM), in combination with NT and CT on the water-stable aggregates, and carbon stabilization in different-sized soil aggregates as well as on substrate-induced respiration (SIR) and the fungal-to-bacterial activity ratio at a soil depth of 0-5 cm. Macroaggregates (>4 mm water- stable aggregates) were 46.8% higher in NT than in CT in June and October 2014 and 52.4% higher with NT in 2015. Microaggregates (0.5- and 0.25-mm aggregates) were higher in CT than NT in both years. The use of CM also increased water-stable aggregates in both years. In 2014, >4-mm aggregate fraction was 6.5% higher with CM than with NM. In 2015, the same parameters were even more effective, with >4-mm and 2-mm aggregate fractions were 23.9% and 34.9% higher with CM respectively. MWD was higher in NT than in CT in both years and CM had slightly increased (but not significantly) this in October. In both years, soil organic carbon (SOC) and nitrogen were significantly higher in NT than in CT, and in October CM further increased these in both tillage systems. In both tillage systems, the highest amounts of SOC was measured in >4-mm aggregate fraction than microaggregates. In both years, microbial SIR was higher in NT than in CT. Further, research is needed to find out long term effect of weed residue mulch in these changes in both tillage systems.

The world’s population is drastically increasing; therefore, an enormous amount of nitrogen and other fertilizers are used to produce enough food for their feeding. Furthermore, since the applied nitrogen amount is not completely absorbed by plants, its big proportion is released to the environment in different ways. The released nitrogen amount damages both humans’ health and the environment. Some technical and agronomical techniques help to minimize the loss of this nitrogen. The fertilizer's loss not only affects farmers' economic condition, but their effects are integrated. Nitrogen fertilizers pollute water, soil, air, as well as our foods. Leaching nitrate can cause eutrophication in sea, lakes, and water bodies. This condition poses a big threat to the lives of fish and other aquatic organisms. It also causes various diseases in humans such as blue baby syndrome, carcinoma, and others. For instance, Nitrate-N (NO3-N) leads to the blue baby syndrome, carcinoma, and other diseases in humans. NO3-N leaching stimulates the growth of blue-green algae and creates hypoxic zones in the water. Moreover, cyanobacteria produce toxins that affect the liver`, kidney, brain, skin, and other parts of the human body, as well as cause complicated diseases. Ammonia and nitrogen oxides contribute to acid rains and have adverse effects on ecosystems. Nitrous oxides (N₂O) deplete the ozone layer, a layer that prevents harmful rays from reaching the earth. N₂O contributes extremely to global warming due to its potentiality. Although Nitrogen fertilizers have contributed to produce high yields in the world, their excessive application has created different problems in our environment. To reduce nitrogen leaching, some agronomical, technical, and other practices are required to be used in the large and small farming system.